On 06/07/2012 09:30 AM, Peter Meerwald wrote:
> v4:
> * remove unused indio_dev pointer in mcp4725_data (Jonathan Cameron)
> * use u16 instead of unsigned short in mcp4725_data (Jonathan Cameron)
> * #include mcp4725.h from linux/iio/dac/
>
> v3:
> * move from staging to drivers/iio
> * switch to chan_spec
> * dev_get_drvdata() -> dev_to_iio_dev()
> * annotate probe() and remove() with __devinit and __devexit
>
> v2 (based on comments from Jonathan Cameron and Lars-Peter Clausen):
> * did NOT switch to chan_spec yet
> * rebase to staging-next tree, update iio header locations
> * dropped dac.h #include, not needed
> * strict_strtol() -> kstrtol()
> * call iio_device_unregister() in remove()
> * everything in one patch
>
Sorry, didn't actually compile this whilst there were outstanding issues
from reading the code. Anyhow few things came up via sparse and and
my arm toolchain... (not sure which version off the top of my head)..
CHECK drivers/iio/dac/mcp4725.c
drivers/iio/dac/mcp4725.c:45:53: warning: incorrect type in argument 2
(different base types)
drivers/iio/dac/mcp4725.c:45:53: expected char const *buf
drivers/iio/dac/mcp4725.c:45:53: got unsigned char [usertype] (
*<noident> )[2]
drivers/iio/dac/mcp4725.c:58:53: warning: incorrect type in argument 2
(different base types)
drivers/iio/dac/mcp4725.c:58:53: expected char const *buf
drivers/iio/dac/mcp4725.c:58:53: got unsigned char [usertype] (
*<noident> )[2]
CC [M] drivers/iio/dac/mcp4725.o
drivers/iio/dac/mcp4725.c: In function 'mcp4725_suspend':
drivers/iio/dac/mcp4725.c:45:25: warning: passing argument 2 of
'i2c_master_send' from incompatible pointer type
include/linux/i2c.h:62:12: note: expected 'const char *' but argument is
of type 'u8 (*)[2]'
drivers/iio/dac/mcp4725.c: In function 'mcp4725_resume':
drivers/iio/dac/mcp4725.c:58:25: warning: passing argument 2 of
'i2c_master_send' from incompatible pointer type
include/linux/i2c.h:62:12: note: expected 'const char *' but argument is
of type 'u8 (*)[2]'
ouch. Fix is pretty obvious.
Please make sure you are building all your code in future. sparse is
simple and useful. If you are feeling thorough, coccicheck and smatch
can catch more issues still.
> Signed-off-by: Peter Meerwald <pmeerw@xxxxxxxxxx>
> ---
> drivers/iio/dac/Kconfig | 11 ++
> drivers/iio/dac/Makefile | 1 +
> drivers/iio/dac/mcp4725.c | 227 +++++++++++++++++++++++++++++++++++++++
> include/linux/iio/dac/mcp4725.h | 16 +++
> 4 files changed, 255 insertions(+)
> create mode 100644 drivers/iio/dac/mcp4725.c
> create mode 100644 include/linux/iio/dac/mcp4725.h
>
> diff --git a/drivers/iio/dac/Kconfig b/drivers/iio/dac/Kconfig
> index a626f03..92fb3a0 100644
> --- a/drivers/iio/dac/Kconfig
> +++ b/drivers/iio/dac/Kconfig
> @@ -118,4 +118,15 @@ config MAX517
> This driver can also be built as a module. If so, the module
> will be called max517.
>
> +config MCP4725
> + tristate "MCP4725 DAC driver"
> + depends on I2C
> + ---help---
> + Say Y here if you want to build a driver for the Microchip
> + MCP 4725 12-bit digital-to-analog converter (DAC) with I2C
> + interface.
> +
> + To compile this driver as a module, choose M here: the module
> + will be called mcp4725.
> +
> endmenu
> diff --git a/drivers/iio/dac/Makefile b/drivers/iio/dac/Makefile
> index 8ab1d26..9ea3cee 100644
> --- a/drivers/iio/dac/Makefile
> +++ b/drivers/iio/dac/Makefile
> @@ -13,3 +13,4 @@ obj-$(CONFIG_AD5764) += ad5764.o
> obj-$(CONFIG_AD5791) += ad5791.o
> obj-$(CONFIG_AD5686) += ad5686.o
> obj-$(CONFIG_MAX517) += max517.o
> +obj-$(CONFIG_MCP4725) += mcp4725.o
> diff --git a/drivers/iio/dac/mcp4725.c b/drivers/iio/dac/mcp4725.c
> new file mode 100644
> index 0000000..d500693
> --- /dev/null
> +++ b/drivers/iio/dac/mcp4725.c
> @@ -0,0 +1,227 @@
> +/*
> + * mcp4725.c - Support for Microchip MCP4725
> + *
> + * Copyright (C) 2012 Peter Meerwald <pmeerw@xxxxxxxxxx>
> + *
> + * Based on max517 by Roland Stigge <stigge@xxxxxxxxx>
> + *
> + * This file is subject to the terms and conditions of version 2 of
> + * the GNU General Public License. See the file COPYING in the main
> + * directory of this archive for more details.
> + *
> + * driver for the Microchip I2C 12-bit digital-to-analog converter (DAC)
> + * (7-bit I2C slave address 0x60, the three LSBs can be configured in
> + * hardware)
> + *
> + * writing the DAC value to EEPROM is not supported
> + */
> +
> +#include <linux/module.h>
> +#include <linux/init.h>
> +#include <linux/i2c.h>
> +#include <linux/err.h>
> +
> +#include <linux/iio/iio.h>
> +#include <linux/iio/sysfs.h>
> +
> +#include <linux/iio/dac/mcp4725.h>
> +
> +#define MCP4725_DRV_NAME "mcp4725"
> +
> +struct mcp4725_data {
> + struct i2c_client *client;
> + u16 vref_mv;
> + u16 dac_value;
> +};
> +
> +#ifdef CONFIG_PM_SLEEP
> +static int mcp4725_suspend(struct device *dev)
> +{
> + u8 outbuf[2];
> +
> + outbuf[0] = 0x3 << 4; /* power-down bits, 500 kOhm resistor */
> + outbuf[1] = 0;
> +
> + return i2c_master_send(to_i2c_client(dev), &outbuf, 2);
> +}
> +
> +static int mcp4725_resume(struct device *dev)
> +{
> + struct iio_dev *indio_dev = dev_to_iio_dev(dev);
> + struct mcp4725_data *data = iio_priv(indio_dev);
> + u8 outbuf[2];
> +
> + /* restore previous DAC value */
> + outbuf[0] = (data->dac_value >> 8) & 0xf;
> + outbuf[1] = data->dac_value & 0xff;
> +
> + return i2c_master_send(to_i2c_client(dev), &outbuf, 2);
> +}
> +
> +static SIMPLE_DEV_PM_OPS(mcp4725_pm_ops, mcp4725_suspend, mcp4725_resume);
> +#define MCP4725_PM_OPS (&mcp4725_pm_ops)
> +#else
> +#define MCP4725_PM_OPS NULL
> +#endif
> +
> +static const struct iio_chan_spec mcp4725_channel = {
> + .type = IIO_VOLTAGE,
> + .indexed = 1,
> + .output = 1,
> + .channel = 0,
> + .info_mask = IIO_CHAN_INFO_RAW_SEPARATE_BIT |
> + IIO_CHAN_INFO_SCALE_SHARED_BIT,
> + .scan_type = IIO_ST('u', 12, 16, 0),
> +};
> +
> +static int mcp4725_set_value(struct iio_dev *indio_dev, int val)
> +{
> + struct mcp4725_data *data = iio_priv(indio_dev);
> + u8 outbuf[2];
> + int ret;
> +
> + if (val >= (1 << 12) || val < 0)
> + return -EINVAL;
> +
> + outbuf[0] = (val >> 8) & 0xf;
> + outbuf[1] = val & 0xff;
> +
> + ret = i2c_master_send(data->client, outbuf, 2);
> + if (ret < 0)
> + return ret;
> + else if (ret != 2)
> + return -EIO;
> + else
> + return 0;
> +}
> +
> +static int mcp4725_read_raw(struct iio_dev *indio_dev,
> + struct iio_chan_spec const *chan,
> + int *val, int *val2, long mask)
> +{
> + struct mcp4725_data *data = iio_priv(indio_dev);
> + unsigned long scale_uv;
> +
> + switch (mask) {
> + case IIO_CHAN_INFO_RAW:
> + *val = data->dac_value;
> + return IIO_VAL_INT;
> + case IIO_CHAN_INFO_SCALE:
> + scale_uv = (data->vref_mv * 1000) >> 12;
> + *val = scale_uv / 1000000;
> + *val2 = scale_uv % 1000000;
> + return IIO_VAL_INT_PLUS_MICRO;
> + }
> + return -EINVAL;
> +}
> +
> +static int mcp4725_write_raw(struct iio_dev *indio_dev,
> + struct iio_chan_spec const *chan,
> + int val, int val2, long mask)
> +{
> + struct mcp4725_data *data = iio_priv(indio_dev);
> + int ret;
> +
> + switch (mask) {
> + case IIO_CHAN_INFO_RAW:
> + ret = mcp4725_set_value(indio_dev, val);
> + data->dac_value = val;
> + break;
> + default:
> + ret = -EINVAL;
> + break;
> + }
> +
> + return ret;
> +}
> +
> +static const struct iio_info mcp4725_info = {
> + .read_raw = mcp4725_read_raw,
> + .write_raw = mcp4725_write_raw,
> + .driver_module = THIS_MODULE,
> +};
> +
> +static int __devinit mcp4725_probe(struct i2c_client *client,
> + const struct i2c_device_id *id)
> +{
> + struct mcp4725_data *data;
> + struct iio_dev *indio_dev;
> + struct mcp4725_platform_data *platform_data = client->dev.platform_data;
> + u8 inbuf[3];
> + int err;
> +
> + if (!platform_data || !platform_data->vref_mv) {
> + dev_err(&client->dev, "invalid platform data");
> + err = -EINVAL;
> + goto exit;
> + }
> +
> + indio_dev = iio_device_alloc(sizeof(*data));
> + if (indio_dev == NULL) {
> + err = -ENOMEM;
> + goto exit;
> + }
> + data = iio_priv(indio_dev);
> + i2c_set_clientdata(client, indio_dev);
> + data->client = client;
> +
> + indio_dev->dev.parent = &client->dev;
> + indio_dev->info = &mcp4725_info;
> + indio_dev->channels = &mcp4725_channel;
> + indio_dev->num_channels = 1;
> + indio_dev->modes = INDIO_DIRECT_MODE;
> +
> + data->vref_mv = platform_data->vref_mv;
> +
> + /* read current DAC value */
> + err = i2c_master_recv(client, inbuf, 3);
> + if (err < 0) {
> + dev_err(&client->dev, "failed to read DAC value");
> + goto exit_free_device;
> + }
> + data->dac_value = (inbuf[1] << 4) | (inbuf[2] >> 4);
> +
> + err = iio_device_register(indio_dev);
> + if (err)
> + goto exit_free_device;
> +
> + dev_info(&client->dev, "MCP4725 DAC registered\n");
> +
> + return 0;
> +
> +exit_free_device:
> + iio_device_free(indio_dev);
> +exit:
> + return err;
> +}
> +
> +static int __devexit mcp4725_remove(struct i2c_client *client)
> +{
> + struct iio_dev *indio_dev = i2c_get_clientdata(client);
> +
> + iio_device_unregister(indio_dev);
> + iio_device_free(indio_dev);
> +
> + return 0;
> +}
> +
> +static const struct i2c_device_id mcp4725_id[] = {
> + { "mcp4725", 0 },
> + { }
> +};
> +MODULE_DEVICE_TABLE(i2c, mcp4725_id);
> +
> +static struct i2c_driver mcp4725_driver = {
> + .driver = {
> + .name = MCP4725_DRV_NAME,
> + .pm = MCP4725_PM_OPS,
> + },
> + .probe = mcp4725_probe,
> + .remove = __devexit_p(mcp4725_remove),
> + .id_table = mcp4725_id,
> +};
> +module_i2c_driver(mcp4725_driver);
> +
> +MODULE_AUTHOR("Peter Meerwald <pmeerw@xxxxxxxxxx>");
> +MODULE_DESCRIPTION("MCP4725 12-bit DAC");
> +MODULE_LICENSE("GPL");
> diff --git a/include/linux/iio/dac/mcp4725.h b/include/linux/iio/dac/mcp4725.h
> new file mode 100644
> index 0000000..91530e6
> --- /dev/null
> +++ b/include/linux/iio/dac/mcp4725.h
> @@ -0,0 +1,16 @@
> +/*
> + * MCP4725 DAC driver
> + *
> + * Copyright (C) 2012 Peter Meerwald <pmeerw@xxxxxxxxxx>
> + *
> + * Licensed under the GPL-2 or later.
> + */
> +
> +#ifndef IIO_DAC_MCP4725_H_
> +#define IIO_DAC_MCP4725_H_
> +
> +struct mcp4725_platform_data {
> + u16 vref_mv;
> +};
> +
> +#endif /* IIO_DAC_MCP4725_H_ */
--
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